JP5649974B2 - Thermoplastic polymer composition and sheet-like molded article comprising the same - Google Patents

Description

  The present invention relates to a thermoplastic polymer composition and a sheet-like molded article comprising the thermoplastic polymer composition. According to the present invention, a sheet-like molded article having excellent flexibility and transparency, excellent surface smoothness and molding processability, and high light transmittance of short wavelength light is provided.

  Conventionally, an acrylic block copolymer having a structure in which a methacrylic ester polymer block is bonded to both ends of an acrylic ester polymer block is flexible and excellent in transparency and weather resistance. It is known to be useful in the field. Such an acrylic block copolymer is formed into a sheet shape, for example, and is used in films and sheets in the optical field, outdoor building materials and the like. However, the acrylic block copolymer alone has insufficient mechanical properties as compared with the styrene block copolymer, so that there are limitations on the fields that can be used.

For example, a polymer composition containing an acrylic block copolymer and an acrylic resin mainly composed of a methacrylic ester unit has been proposed (see Patent Documents 1 and 2). However, although these polymer compositions are superior in mechanical properties compared to the acrylic block copolymer alone, they are cooled by the tackiness of the obtained sheet-like molded article when molding the sheet-like molded article by extrusion molding. The surface of the sheet-like molded product obtained by extrusion molding is inferior in molding processability such as over-adhesion to the roll, resulting in decreased productivity, or the composition has a high viscosity, and there are fine textured irregularities on the surface. This occurred, and a good sheet-like molded body could not be obtained, leaving room for improvement.
Moreover, in order to improve the impact strength of an acrylic resin mainly composed of methacrylic ester units, a resin composition in which an acrylic block copolymer is blended with an acrylic resin has been proposed (see Patent Documents 3 and 4). However, the resin compositions specifically disclosed in these documents are poor in flexibility, and in thin-walled molded products such as sheet-like molded products, cracks and the like occur when stress is applied, causing cracks and the like. There was a possibility, and the field of use was limited.

Further, Patent Documents 5 and 6 disclose a laminate film to other materials characterized by weather resistance, flexibility, transparency, etc. as a sheet-like molded body composed of a composition mainly composed of an acrylic block copolymer. Has been. However, these documents do not specifically describe a method for improving various physical properties by adding an acrylic resin.
Patent Document 7 discloses a cover sheet made of a composition of an acrylic block copolymer and an acrylic resin, and Patent Document 8 has an optical member made of a composition containing an acrylic block copolymer. Each has been proposed. However, when a sheet-like molded body is formed by extrusion molding of an acrylic block copolymer alone or a composition comprising an acrylic block copolymer and an acrylic resin, fine streaks are formed on the surface of the sheet-like molded body. As a result, there was a room for improvement.

Japanese Patent Laid-Open No. 10-168271 JP 2003-277574 A JP 2000-154329 A WO02 / 092696 JP 2002-338707 A JP 2003-128809 A Japanese Patent Application Laid-Open No. 11-349782 WO09 / 054553 Japanese Patent Publication No. 7-25859 JP-A-11-335432 JP-A-6-93060

Macromol. Chemical Physics 201, 1108-1114 (2000)

  An object of the present invention is to provide a sheet-like molded article having excellent flexibility and transparency, excellent surface smoothness and molding processability, and high light transmittance of short wavelength light, and a thermoplastic polymer composition providing the same. There is to do.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by blending an acrylic resin in a specific ratio with respect to a specific acrylic block copolymer. The headline and the present invention were completed.
That is, according to the present invention, the above object is a thermoplastic polymer composition comprising an acrylic block copolymer (A) and an acrylic resin (B);
The acrylic block copolymer (A) has a molecular structure in which a polymer block (a2) mainly composed of methacrylate units is bonded to both ends of the polymer block (a1) mainly composed of acrylate units. An acrylic block copolymer having at least one thereof, having a weight average molecular weight of 10,000 to 100,000;
Content of acrylic block copolymer (A1) and polymer block (a2) whose acrylic block copolymer (A) is 40 mass% or more and 80 mass% or less of content of polymer block (a2) Including an acrylic block copolymer (A2) in which is 10 mass% or more and less than 40 mass%;
The acrylic resin (B) is mainly composed of methacrylate units;
A thermoplastic polymer composition having a mass ratio [(A) / (B)] of the acrylic block copolymer (A) and the acrylic resin (B) of 97/3 to 10/90, and the thermoplastic heavy This is achieved by providing a sheet-like molded body comprising the combined composition.

  One preferred embodiment of the present invention is the above thermoplastic polymer composition and sheet form using an acrylic resin (B) having a melt flow rate of 15 g / 10 min or more at 230 ° C. and 37.3 N. It is a molded body.

  One of the preferred embodiments of the present invention is the thermoplastic polymer composition described above using an acrylic resin (B) having a melt flow rate at 230 ° C. and 37.3 N of less than 15 g / 10 minutes, and It is a sheet-like molded object.

  Preferably, in the present invention, the content of the acrylic block copolymer (A1) is 5% by mass or more based on the total amount of the acrylic block copolymer (A), and the acrylic block copolymer The average content of the polymer block (a2) in (A) is 35% by mass or more and 80% by mass or less.

  Preferably, the sheet-like molded product of the present invention is an average light transmission at a light wavelength of 400 nm to 500 nm at a D65 light source obtained by a spectral light transmittance measurement method, a 2 ° viewing angle, a measurement temperature of 25 ° C., and an optical path length of 15 mm. The rate is 40% or more.

  According to the present invention, by adopting the above-described configuration, a sheet-like molded article having excellent flexibility and transparency, excellent surface smoothness and molding processability, and high light transmittance of short-wavelength light, and heat that provides the same. A plastic resin composition is provided.

Hereinafter, the present invention will be described in detail.
The thermoplastic polymer composition of the present invention comprises:
A thermoplastic polymer composition comprising an acrylic block copolymer (A) and an acrylic resin (B);
The acrylic block copolymer (A) has a molecular structure in which a polymer block (a2) mainly composed of methacrylate units is bonded to both ends of the polymer block (a1) mainly composed of acrylate units. An acrylic block copolymer having at least one thereof, having a weight average molecular weight of 10,000 to 100,000;
Content of acrylic block copolymer (A1) and polymer block (a2) whose acrylic block copolymer (A) is 40 mass% or more and 80 mass% or less of content of polymer block (a2) Including an acrylic block copolymer (A2) in which is 10 mass% or more and less than 40 mass%;
The acrylic resin (B) is mainly composed of methacrylate units;
It is a thermoplastic polymer composition having a mass ratio [(A) / (B)] of the acrylic block copolymer (A) and the acrylic resin (B) of 97/3 to 10/90.

  The acrylic block copolymer (A) which is the first component in the present invention is a polymer block mainly composed of methacrylate units at both ends of the polymer block (a1) mainly composed of acrylate units. Acrylic block copolymer having at least one structure in which (a2) is bonded, that is, a structure of (a2)-(a1)-(a2) (in the structure, “-” indicates a chemical bond). It is.

  In the acrylic block copolymer (A), the polymer block (a1) mainly composed of an acrylate unit is a polymer block mainly composed of an acrylate unit. Examples of the acrylic ester for forming the polymer block (a1) include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and sec sec acrylic acid. -Butyl, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate, isobornyl acrylate, phenyl acrylate, acrylic Examples include benzyl acid, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-methoxyethyl acrylate, and the like. Among these, from the viewpoint of improving flexibility, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, phenoxyethyl acrylate, 2-methoxy acrylate Acrylic acid alkyl esters such as ethyl are preferable, and n-butyl acrylate and 2-ethylhexyl acrylate are more preferable. The polymer block (a1) may be composed of one kind of these acrylate esters or may be composed of two or more kinds.

As long as the object and effect of the present invention are not hindered, the polymer block (a1) may be an acrylate unit having a reactive group, for example, other than glycidyl acrylate, allyl acrylate, or an acrylate unit. These polymerizable monomer units, for example, monomers such as the following methacrylic acid esters, methacrylic acid, acrylic acid, aromatic vinyl compounds, acrylonitrile, methacrylonitrile, and olefins may be included as a copolymerization component. The amount of these acrylate ester units or other polymerizable monomer units having a reactive group is preferably a small amount from the viewpoint of expressing the effects of the present invention, preferably 20% by mass or less, more preferably 10% by mass or less. is there.

  The polymer block (a2) mainly composed of methacrylic acid ester units in the acrylic block copolymer (A) is a polymer block mainly composed of methacrylic acid ester units. Examples of the methacrylic acid ester for forming the polymer block (a2) include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec sec methacrylate. -Butyl, tert-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, methacryl Examples include benzyl acid, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, and the like. Among these, from the viewpoint of improving transparency and heat resistance, methacrylic acid such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, and isobornyl methacrylate. Alkyl esters are preferred, and methyl methacrylate is more preferred. The polymer block (a2) may be composed of one of these methacrylic acid esters or may be composed of two or more.

  In addition, as long as the object and effect of the present invention are not hindered, the polymer block (a2) may be a methacrylic acid ester unit having a reactive group, for example, glycidyl methacrylate, allyl methacrylate, or other than methacrylic ester units. A small amount, preferably 20% by mass or less, of a polymerizable monomer unit, for example, a monomer such as acrylic acid ester, methacrylic acid, acrylic acid, aromatic vinyl compound, acrylonitrile, methacrylonitrile, olefin as a copolymerization component. Preferably it may contain 10 mass% or less.

  The acrylic block copolymer (A) comprises a polymer block (a1) mainly composed of one acrylate unit and a polymer block (a2) mainly composed of two methacrylate units (a2). )-(A1)-(a2) having at least one structure in the molecule. The molecular chain form of the acrylic block copolymer (A) is not particularly limited, and may be, for example, linear, branched, or radial. Among them, it is preferable to use a triblock body represented by (a2)-(a1)-(a2). Here, the molecular weight and composition of (a2) at both ends of (a1) may be the same or different from each other.

  As long as the purpose and effect of the present invention are not hindered, the acrylic block copolymer (A) is a polymer block different from these polymer blocks (a1) and (a2). You may have a polymer block (c) induced | guided | derived from monomers other than a methacrylic acid ester monomer. The form of the bond between the polymer block (c) and the polymer block (a1) mainly composed of the acrylate unit and the polymer block (a2) mainly composed of the methacrylic ester unit is not particularly limited. , (A2)-((a1)-(a2)) n- (c) and (c)-(a2)-((a1)-(a2)) n- (c) (n is 1 It is an integer of ~ 20).

  Examples of the monomer constituting the polymer block (c) include olefins such as ethylene, propylene, 1-butene, isobutylene and 1-octene; conjugated diene compounds such as 1,3-butadiene, isoprene and myrcene; styrene, α -Aromatic vinyl compounds such as methylstyrene, p-methylstyrene, m-methylstyrene; vinyl acetate, vinylpyridine, acrylonitrile, methacrylonitrile, vinyl ketone, vinyl chloride, vinylidene chloride, vinylidene fluoride, acrylamide, methacrylamide, ε -Caprolactone, valerolactone and the like.

  The acrylic block copolymer (A) used in the present invention may have a functional group such as a hydroxyl group, a carboxyl group, an acid anhydride, or an amino group in the molecular chain or at the molecular chain end as necessary. .

  The acrylic block copolymer (A) has a weight average molecular weight of 10,000 to 100,000, and the thermoplastic polymer composition of the present invention and the flexibility of a sheet-like molded article comprising the thermoplastic polymer composition From the viewpoint of improving the properties, moldability, etc., it is preferably 30,000 to 80,000, more preferably 50,000 to 70,000. When the weight average molecular weight of the acrylic block copolymer (A) is less than 10,000, sufficient melt tension cannot be maintained in melt extrusion molding, and it is difficult to obtain a good sheet-like molded product. The mechanical properties such as the breaking strength of the sheet-like molded product are inferior. On the other hand, if it is greater than 100,000, the molten resin becomes highly viscous, and the surface of the sheet-like molded body obtained by melt extrusion molding has fine grain-like irregularities and unevenness due to unmelted material (high molecular weight body). It tends to occur and it is difficult to obtain a good sheet-like molded product.

  In the acrylic block copolymer (A), the weight average molecular weight of the polymer block (a1) mainly composed of an acrylate unit is preferably 2,000 to 80,000, and is preferably 5,000 to 70,000. More preferably, it is 000. The weight average molecular weight of the polymer block (a2) mainly composed of methacrylic acid ester units is preferably 2,000 to 80,000, and more preferably 5,000 to 70,000.

  The ratio (Mw / Mn) of the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the acrylic block copolymer (A) is preferably in the range of 1.01 or more and less than 1.50. More preferably, it is in the range of 1.01 to 1.35. By taking such a range, the content of the unmelted material which causes the generation of flaws in the sheet-like molded body made of the thermoplastic polymer composition of the present invention can be made extremely small.

  From the viewpoint of improving the surface smoothness and molding processability of the sheet-like molded article made of the thermoplastic polymer composition of the present invention, the constituent component of the acrylic block copolymer (A) has two kinds of specific structures described above. The acrylic block copolymer having a content of the polymer block (a2) mainly composed of a methacrylic acid ester unit is 40% by mass or more and 80% by mass or less. It is important to include the acrylic block copolymer (A2) in which the content of the polymer (A1) and the polymer block (a2) mainly composed of methacrylic acid ester units is 10% by mass or more and less than 40% by mass. When the constituent of the acrylic block copolymer (A), which is a constituent of the thermoplastic polymer composition of the present invention, is composed of one kind of the acrylic block copolymer (A1), the acrylic block copolymer (A1 ) Since a unique periodic phase-separated microphase separation structure is formed, anisotropy appears in the sheet-like molded body obtained by the melt extrusion method, resulting in streak-like irregularities on the surface of the sheet-like molded body It is estimated that the surface smoothness is lowered. In particular, from the viewpoint of improving moldability, flexibility, transparency, and light transmittance of short wavelength light, the content of the polymer block (a2) of the acrylic block copolymer (A1) is 50% by mass. The content is preferably 65% by mass or less and more preferably 50% by mass or more and 55% by mass or less. Furthermore, from the viewpoint of further improving the surface smoothness and molding processability of the thermoplastic polymer composition of the present invention and the sheet-like molded product comprising the same, the polymer block (a2) of the acrylic block copolymer (A2) The content is preferably 15% by mass or more and less than 40% by mass, and more preferably 23% by mass or more and 35% by mass or less. When the content of the polymer block (a2) in the acrylic block copolymer (A1) is less than 40% by mass, the compatibility with the acrylic resin (B) is lowered, and transparency / moldability In addition, since the light loss of short wavelength light in the long optical path is particularly large, the light transmittance of short wavelength light is lowered. On the other hand, when the content of the polymer block (a2) in the acrylic block copolymer (A1) is larger than 80% by mass, the thermoplastic polymer composition of the present invention and the thermoplastic polymer composition are used. The elastic modulus of the resulting sheet-like molded body is increased and the flexibility is poor. Further, when the content of the polymer block (a2) in the acrylic block copolymer (A2) is less than 10% by mass, the thermoplastic polymer composition of the present invention and the sheet-like molded product comprising the same Surface sticking occurs, making it unsuitable as a molding material. On the other hand, when the content of the polymer block (a2) in the acrylic block copolymer (A2) is 40% by mass or more, the thermoplastic polymer composition of the present invention and the sheet-like molded product comprising the same Elastic modulus increases and is inferior in flexibility.

  The blending ratio of the acrylic block copolymer (A1) and the acrylic block copolymer (A2) constituting the acrylic block copolymer (A) depends on the thermoplastic polymer composition of the present invention and the thermoplastic heavyweight. From the viewpoint of improving the molding processability, flexibility, and light transmittance of short-wavelength light of the sheet-like molded body comprising the coalescence composition, the content of the acrylic block copolymer (A1) is the acrylic block copolymer ( The total amount of A) is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 40% by mass or more. Although there is no restriction | limiting in particular in the upper limit of content of an acryl-type block copolymer (A1), Usually, it is 90 mass% or less, 80 mass% or less is preferable, and it is more preferable that it is 75 mass% or less. When the content of the acrylic block copolymer (A1) is smaller than the above range, the melt viscosity of the thermoplastic polymer composition of the present invention is lowered, and the melt tension necessary for melt extrusion molding can be sufficiently maintained. Therefore, it is difficult to obtain a good sheet-like molded body. In addition, the compatibility with the acrylic resin (B) decreases, and particularly when the acrylic resin (B) having a melt flow rate of less than 15 g / 10 min at 230 ° C. and 37.3 N is used together, In particular, since the short wavelength light loss increases, the light transmittance of short wavelength light tends to decrease.

  The average content of the polymer block (a2) in the acrylic block copolymer (A) is from 35% by mass to 80% by mass from the viewpoints of transparency, flexibility, molding processability, and surface smoothness. Is preferable, 40 mass% or more and 70 mass% or less is more preferable, and 40 mass% or more and 60 mass% or less is further more preferable. When the average content of the polymer block (a2) in the acrylic block copolymer (A) is smaller than the above range, surface sticking of the thermoplastic polymer composition of the present invention and the sheet-like molded product formed therefrom occurs. , Tend to be unsuitable as a molding material. When the average content of the polymer block (a2) in the acrylic block copolymer (A) is larger than the above range, the thermoplastic polymer composition of the present invention and a sheet comprising the thermoplastic polymer composition There exists a tendency for the tensile elasticity modulus of a molded object to increase and to be inferior to a softness | flexibility.

  It does not specifically limit as a manufacturing method of an acryl-type block copolymer (A), The method according to a well-known method is employable. For example, as a method for obtaining the acrylic block copolymer (A), a method of living polymerization of monomers constituting each block is generally used. Examples of such living polymerization methods include anionic polymerization in the presence of a mineral acid salt such as an alkali metal or alkaline earth metal salt using an organic alkali metal compound as a polymerization initiator (see Patent Document 9), organic A method of anionic polymerization using an alkali metal compound as a polymerization initiator in the presence of an organoaluminum compound (see Patent Document 10), a method of polymerizing using an organic rare earth metal complex as a polymerization initiator (see Patent Document 11), α-halogenated ester Examples include a method of radical polymerization using a compound as an initiator in the presence of a copper compound (see Non-Patent Document 1). Moreover, the method of polymerizing the monomer which comprises each block using a polyvalent radical polymerization initiator and a polyvalent radical chain transfer agent, and manufacturing as a mixture containing the acryl-type block copolymer (A) of this invention, etc. Also mentioned. Among these methods, an acrylic block copolymer is obtained with high purity, and the molecular weight and composition ratio can be easily controlled and economical. A method of anionic polymerization in the presence of an aluminum compound is recommended.

  The acrylic resin (B) which is a blending component in the present invention is an acrylic resin mainly composed of methacrylic acid ester units. From the viewpoint of improving the transparency, molding processability and the like of the thermoplastic polymer composition of the present invention and the sheet-like molded product comprising the thermoplastic polymer composition, a homopolymer of methacrylic acid ester or a methacrylic acid ester unit is used. A copolymer having a main component is preferable. Examples of the methacrylic acid ester which is a main component constituting the acrylic resin (B) include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic acid. sec-butyl, tert-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, Examples thereof include benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate and the like. Among these, from the viewpoint of compatibility with the acrylic block copolymer contained in the thermoplastic polymer composition of the present invention, and from the viewpoint of the transparency and moldability of the thermoplastic polymer composition, methyl methacrylate is used. It is preferably an alkyl ester of methacrylic acid such as ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate or isobornyl methacrylate, and more preferably methyl methacrylate. One or more of these methacrylic acid esters can be used.

  As long as the purpose and effect of the present invention are not hindered, a polymerizable monomer unit having a reactive group as a methacrylic acid ester unit constituting the acrylic resin (B), for example, a monomer such as glycidyl methacrylate or allyl methacrylate is used. A small amount, preferably 20% by mass or less, more preferably 10% by mass or less may be contained as a constituent component.

  When the acrylic resin (B) is a copolymer mainly composed of a methacrylic acid ester unit, the other monomer that can be copolymerized with the methacrylic acid ester constituting the copolymer is not particularly limited. Methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, acrylic acid n-hexyl, cyclohexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate, isobornyl acrylate, phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, acrylic acid 2 Acrylic esters such as methoxyethyl, glycidyl acrylate and allyl acrylate; unsaturated carboxylic acids such as methacrylic acid, acrylic acid and maleic anhydride; olefins such as ethylene, propylene, 1-butene, isobutylene and 1-octene; 1 Conjugated diene compounds such as 1,3-butadiene, isoprene, and myrcene; aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, and m-methylstyrene; vinyl acetate, vinylpyridine, acrylonitrile, methacrylonitrile, vinyl ketone , Vinyl chloride, vinylidene chloride, vinylidene fluoride, acrylamide, methacrylamide and the like. One or more of these monomers can be used.

  When the acrylic resin (B) is a copolymer, the form of copolymerization is not particularly limited, and random copolymerization, block copolymerization, alternating copolymerization, and the like are generally used. In the thermoplastic polymer composition of the present invention and a sheet-like molded product comprising the thermoplastic polymer composition, the acrylic resin (B) is composed of a methacrylic ester polymer block and an acrylic ester polymer block. When a block copolymer is used, a thermoplastic polymer composition excellent in adhesive performance or adhesive performance and a sheet-like molded product made of the thermoplastic polymer composition can be obtained.

  Moreover, there is no restriction | limiting in particular about the stereoregularity of an acrylic resin (B), What is isotactic, heterotactic, or syndiotactic can be used.

  Although there is no restriction | limiting in particular in the weight average molecular weight of an acrylic resin (B), Usually, it is preferable that it is 30,000-500,000, and it is more preferable that it is 70,000-200,000. Moreover, although the acrylic resin (B) used for this invention can be used individually by 1 type, the mixture of 2 or more types of acrylic resins from which a weight average molecular weight etc. differ can also be used.

  Although there is no special restriction | limiting in the fluidity | liquidity of the acrylic resin (B) used by this invention, The light transmission of the short wavelength light of the sheet-like molded object which consists of the thermoplastic polymer composition of this invention, and this thermoplastic polymer composition From the viewpoint of improving the rate, the melt flow rate at 230 ° C. and 37.3 N is preferably 15 g / 10 min or more. The upper limit of the melt flow rate is not particularly limited, but the difference in melt viscosity from the acrylic block copolymer (A) becomes large. If the melt flow rate is too large, sufficient melt tension can be maintained particularly in melt extrusion molding. Therefore, it is difficult to obtain a good molded product, and mechanical properties such as breaking strength of the obtained molded product are inferior. Therefore, the range of the melt flow rate is preferably 40 g / 10 min or less, more preferably 15 g / 10 min or more and 30 g / 10 min or less, and further preferably 15 g / 10 min or more and 25 g / 10 min or less. preferable. On the other hand, when the melt flow rate at 230 ° C. and 37.3 N of the acrylic resin (B) is less than 15 g / 10 minutes, the transparency and the surface smoothness of the sheet-like molded product are improved when extruded. There is an effect to.

  A commercial item may be used for the acrylic resin (B) used by this invention. Examples of such commercially available acrylic resins include “Parapet H1000B” (MFR: 22 g / 10 min (230 ° C., 37.3 N)) and “Parapet GF” (MFR: 15 g / 10 min (230 ° C., 37.3 N). )), “Parapet EH” (MFR: 1.3 g / 10 min (230 ° C., 37.3 N)), “Parapet HRL” (MFR: 2.0 g / 10 min (230 ° C., 37.3 N)) and “ Parapet G ”(MFR: 8.0 g / 10 min (230 ° C., 37.3 N)) [all trade names, manufactured by Kuraray Co., Ltd.] and the like.

  Mass ratio of acrylic block copolymer (A) and acrylic resin (B) in the thermoplastic polymer composition of the present invention and a sheet-like molded article comprising the thermoplastic polymer composition [(A) / (B )] Is 97/3 to 10/90. When the proportion of the acrylic resin (B) is smaller than the above range (when the proportion of the acrylic block copolymer (A) is larger than the above range), a sheet-like molded body obtained by melt extrusion molding using a T die. Fine streak-like irregularities are generated on the surface of the sheet, and it is difficult to obtain a sheet-like molded article having good surface smoothness. On the other hand, when the proportion of the acrylic resin (B) is larger than the above range (when the proportion of the acrylic block copolymer (A) is smaller than the above range), the thermoplastic polymer composition and the sheet-like molded body comprising the same The tensile elastic modulus increases and the flexibility decreases. From the viewpoint of satisfying the molding processability and flexibility of the thermoplastic polymer composition and the sheet-like molded product comprising the same, the mass ratio of the acrylic block copolymer (A) to the acrylic resin (B) is 95/5 to 5/5. 10/90 is preferable, 90/10 to 20/80 is more preferable, and 85/15 to 30/70 is still more preferable. In particular, from the viewpoint of emphasizing flexibility, the mass ratio of the acrylic block copolymer (A) to the acrylic resin (B) is preferably 85/15 to 50/50, and 85/15 to 60/40. Is more preferable, and 80/20 to 65/35 is more preferable.

  The thermoplastic polymer composition of the present invention and the sheet-shaped molded article comprising the thermoplastic polymer composition are preferably composed of only the acrylic block copolymer (A) and the acrylic resin (B). If it is a range which does not impair the effect of this invention, other polymers etc. may be contained as needed other than the above-mentioned acrylic block copolymer (A) and acrylic resin (B). Other polymers include, for example, olefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, polynorbornene; ethylene ionomers; polystyrene, styrene-maleic anhydride copolymers, high Styrenic resins such as impact polystyrene, AS resin, ABS resin, AES resin, AAS resin, ACS resin, MBS resin; methyl methacrylate-styrene copolymer; polyester resin such as polyethylene terephthalate, polybutylene terephthalate, polylactic acid; nylon 6 Polyamide resins such as nylon 66 and polyamide elastomers; ester polyurethane elastomers, ether polyurethane elastomers, non-yellowing ester polyurethane elastomers, non-yellowing carbonate polyurethanes Polyurethane resins such as emissions elastomer; polycarbonate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene - vinyl alcohol copolymer, polyacetal, polyvinylidene fluoride, modified polyphenylene ether, polyphenylene sulfide, and silicone rubber-modified resins. Among these, AS resin and polyvinylidene fluoride are preferably used from the viewpoint of compatibility with the acrylic block copolymer contained in the thermoplastic polymer composition of the present invention.

  Furthermore, the thermoplastic polymer composition of the present invention and the sheet-like molded product comprising the thermoplastic polymer composition may be added to various known additives (for example, rubbers, lubricants, etc. within the range not impairing the effects of the present invention. , Antioxidants, light stabilizers, colorants, antistatic agents, flame retardants, etc.), fillers (for example, fiber reinforcing agents such as glass fibers, inorganic fillers, etc.) and the like. For example, specific examples of rubbers that can be blended include acrylic rubber; silicone rubber; styrene thermoplastic elastomers such as SEPS, SEBS, and SIS; olefin rubbers such as IR, EPR, and EPDM. One or more of these can be used. Examples of other additives and fillers that can be blended include mineral oil softeners such as paraffinic oils and naphthenic oils for improving fluidity during molding; improvement or increase in heat resistance, weather resistance, etc. Inorganic fillers such as calcium carbonate, talc, carbon black, titanium oxide, silica, clay, barium sulfate, magnesium carbonate for the purpose; glass fiber for reinforcement, inorganic fiber or organic fiber such as carbon fiber; heat stabilizer An antioxidant, a light stabilizer, an adhesive, a tackifier, a plasticizer, an antistatic agent, a foaming agent, a colorant, and a dyeing agent. Among these additives, in order to further improve heat resistance and weather resistance, it is practically preferable to add a heat stabilizer, an antioxidant and the like.

  The method for preparing the thermoplastic polymer composition of the present invention is not particularly limited, but in order to improve the dispersibility of each component constituting the thermoplastic polymer composition, a method of melt kneading and mixing is recommended. Examples of the preparation method include a method of melt-kneading the acrylic block copolymer (A) and the acrylic resin (B). If necessary, these and other polymers and additives described above may be used. The acrylic block copolymer (A) may be mixed with the acrylic resin (B) after being mixed together with the other polymer and additives described above. The mixing operation can be performed using a known mixing or kneading apparatus such as a kneader ruder, an extruder, a mixing roll, or a Banbury mixer. In particular, it is preferable to use a twin screw extruder from the viewpoint of improving the kneadability and compatibility between the acrylic block copolymer (A) and the acrylic resin (B). The temperature at the time of mixing and kneading is suitably adjusted according to the melting temperature of the acrylic block copolymer (A), acrylic resin (B), etc. to be used, and is usually within the range of 110 ° C to 300 ° C. Mix at temperature. In this way, the thermoplastic polymer composition of the present invention can be obtained in any form such as pellets and powders. The thermoplastic polymer composition in the form of pellets, powders and the like is suitable for use as a molding material.

  The above thermoplastic polymer composition is converted into a T-die method (lamination method, coextrusion method, etc.), inflation method (coextrusion method, etc.), compression molding method, blow molding method, calendar molding method, vacuum molding method, injection molding method. Sheet-like molded products can be manufactured by any melt molding method such as insert method, two-color method, press method, core back method, sandwich method, etc., and solution casting method. In view of the above, melt extrusion molding by T-die method or inflation method is preferable, and T-die method is more preferable from the viewpoint of excellent productivity and thickness accuracy.

 The T die is not particularly limited, and examples thereof include known dies such as a coat hanger type and a straight type. Examples of the material of the die include SCM steel and stainless steel such as SUS, but are not limited thereto.

  In the case of the production method by the T-die method, an extruder type melt extrusion apparatus equipped with a single screw or twin screw can be used. The melt extrusion temperature for producing the sheet-like molded product of the present invention is preferably 100 to 350 ° C, more preferably 150 to 300 ° C. Moreover, when melt-kneading using a melt-extrusion apparatus, it is preferable to perform the melt-kneading under reduced pressure or the melt-kneading under nitrogen stream from a viewpoint of coloring suppression. It is also possible to stretch in a uniaxial or biaxial direction simultaneously with or after extrusion.

  A sheet-like molded article made of the thermoplastic polymer composition of the present invention is a molded article obtained by molding a thermoplastic polymer composition into a sheet. In general, a sheet-like molded body having a thickness of 0.005 mm or more and 0.25 mm or less is referred to as a film, and a sheet-like molded body having a thickness greater than 0.25 mm is referred to as a sheet. The thickness of the sheet-like molded body of the present invention is preferably 0.025 mm or more and 10 mm or less, and more preferably 0.05 mm or more and 5 mm or less from the viewpoint of flexibility and the like.

  In a sheet-like molded article comprising the thermoplastic polymer composition of the present invention, a D65 light source obtained by a spectroscopic light transmittance measurement method, a 2 ° viewing angle, a measurement temperature of 25 ° C., and an optical path length of 15 mm at an optical wavelength of 400 nm to 500 nm. When the average light transmittance is 40% or more, the wavelength dependency of the light transmittance is lowered. That is, since the difference between the light transmittance at a wavelength of 400 nm to 500 nm and the light transmittance at 501 nm to 780 nm becomes small, it can be suitably used as an optical member that guides light from the longitudinal direction of the molded body.

  The use of the thermoplastic polymer composition of the present invention and the sheet-like molded product comprising the same is not particularly limited, but is used in various applications such as the optical field, food field, medical field, consumer field, automobile field, and electric / electronic field. can do. In particular, the sheet-like molded article of the present invention is excellent in surface smoothness and molding processability, excellent in flexibility, and excellent in optical characteristics such as light transmittance of short wavelength light. Optical devices represented by terminal boards, printed wiring boards, speakers, microscopes, binoculars, cameras, watches, etc., as well as cameras, VTRs, projection TVs, etc., filters as video / optical recording / optical communication / information equipment related parts , Prism, Fresnel lens, various optical discs (VD, CD, DVD, MD, LD, etc.), substrate protective film, optical switch, optical connector, liquid crystal display, light guide film / sheet for liquid crystal display, flat panel display, flat panel display Light guide film / sheet, plasma display, light guide film for plasma display Rum sheet, retardation film / sheet, polarizing film / sheet, polarizing plate protective film / sheet, wavelength plate, light diffusion film / sheet, prism film / sheet, reflective film / sheet, antireflection film / sheet, viewing angle expansion Known optics such as films and sheets, antiglare films and sheets, brightness enhancement films and sheets, display element substrates for liquid crystal and electroluminescence applications, touch panels, light guide films and sheets for touch panels, spacers between various front plates and various modules It can be suitably applied to applications. Specifically, for example, various liquid crystal display elements such as mobile phones, digital information terminals, pagers, navigation, in-vehicle liquid crystal displays, liquid crystal monitors, light control panels, displays for OA devices, displays for AV devices, and electroluminescence displays It can be used for an element or a touch panel. Moreover, from the point which is excellent in a weather resistance, a softness | flexibility, etc., for example, a building interior / exterior member, a curtain wall, a roof member, a roofing material, a window member, a gutter, an exterior, a wall material, a flooring material It can also be suitably applied to known building material applications such as construction materials, road construction members, retroreflective films and sheets, agricultural films and sheets, lighting covers, signboards, and translucent sound insulation walls.

  The sheet-like molded article made of the thermoplastic polymer composition of the present invention may be used alone, or may be used in combination of a plurality, or may be used in combination with a member other than the sheet-shaped molded article of the present invention. Good.

  The sheet-like molded body made of the thermoplastic polymer composition of the present invention may be used as a single layer or as a laminate of two or more layers. When using as a laminated body, only the sheet-like molded object of this invention may be laminated | stacked, and the sheet-like molded object of this invention and another raw material may be laminated | stacked. When forming a laminated body, it is possible to manufacture each layer by a well-known method. In other words, a co-extrusion method by extrusion such as T-die method or inflation method, a fusion method such as heat fusion, ultrasonic fusion, high frequency fusion, or a known adhesive that cures by ultraviolet rays, heat, radiation, etc. And the like. Further, a known primer may be applied to the surface to be fused or bonded, and corona discharge treatment, plasma treatment, or the like may be performed. When forming a laminated body, the order of lamination | stacking, printing, provision of surface shape, and cutting to the target magnitude | size is not specifically limited. When forming the optical component in combination with other materials, such as when using the sheet-like molded product of the present invention as a laminated optical component, the other material can be selected as appropriate according to the desired characteristics. Any of organic compounds or polymers, inorganic substances, compositions containing these, and the like can be used. Specifically, for example, when forming an optical component by laminating the sheet-like molded body of the present invention and other materials, the other materials include organic compounds such as hard coat materials, antireflection materials, and liquid crystals. Or an organic polymer such as a composition, a cyclic olefin ring-opening polymer or a hydrogenated product thereof, an addition polymerization type cyclic olefin polymer, an aliphatic olefin resin, an acrylic polymer, a polycarbonate resin, a liquid crystal polymer, or the like Commercially available or known materials such as compositions, inorganic substances such as soda glass and quartz glass, or compositions can be used.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Various physical properties in Examples and Comparative Examples were measured or evaluated by the following methods.

(1) Weight average molecular weight (Mw)
The weight average molecular weights (Mw) of the acrylic block copolymers (A1), (A2) and the acrylic resin (B) were determined by gel permeation chromatography (hereinafter abbreviated as GPC) in terms of polystyrene equivalent molecular weight.
-Equipment: GPC equipment "HLC-8020" manufactured by Tosoh Corporation
Separation column: “TSKgel GMHXL”, “G4000HXL” and “G5000HXL” manufactured by Tosoh Corporation are connected in series. Eluent: Tetrahydrofuran Eluent flow rate: 1.0 ml / min Column temperature: 40 ° C.
・ Detection method: Differential refractive index (RI)

(2) Melt flow rate (MFR)
The melt flow rate (MFR) of the acrylic resin (B) was measured under the conditions of 230 ° C., 37.3 N, and 10 minutes in accordance with ISO 1133.

(3) Composition ratio of each polymer block The composition ratio of each polymer block in the acrylic polymer block was determined by ¹ H-NMR ( ¹ H-nuclear magnetic resonance) measurement.
・ Device: JEOL Nuclear Magnetic Resonance Device “JNM-LA400”
・ Deuterated solvent: Deuterated chloroform

(4) Transparency Using the thermoplastic polymer composition obtained in the following examples or comparative examples, a sheet-like molding having a thickness of 0.1 mm molded at a cylinder temperature and a die temperature of 220 ° C. by a T-die extruder. A 50 mm × 50 mm test piece was cut out from the body, and the haze value and total light transmittance were measured with a direct reading haze meter (manufactured by Nippon Denshoku) in accordance with JIS K7105.

(5) Flexibility (tensile modulus)
Using a thermoplastic polymer composition obtained in the following examples or comparative examples, a JIS No. 3 stamping was performed from a sheet-like molded article having a thickness of 0.1 mm molded at a cylinder temperature and a die temperature of 220 ° C. by a T-die extruder. A test piece was punched out with a blade, and the tensile modulus was measured according to JIS K7127.

(6) Surface smoothness 0.1 mm thick sheet molded at a cylinder temperature and a die temperature of 220 ° C. by a T-die extruder using the thermoplastic polymer composition obtained in the following examples or comparative examples. The surface state of the shaped molded body was visually evaluated and used as an index of surface smoothness.
◯: The surface is smooth Δ: The surface is almost smooth, but some of the surface has streaks or grainy irregularities.
X: The surface is not smooth due to streaks and grainy irregularities

(7) Molding processability Using a thermoplastic polymer composition obtained in the following Examples or Comparative Examples, a sheet shape having a thickness of 0.1 mm at a cylinder temperature and a die temperature of 220 ° C. by a T-die extruder. The state of film formation when the molded body was molded was visually evaluated, and this was used as an index of molding processability.
○: Good film forming condition Δ: Thickness fluctuation and extrusion amount fluctuation are small, but melt viscosity is high and molding range is narrow ×: Thickness unevenness due to surging phenomenon and discharge at both ends of sheet-like molded body due to draw resonance phenomenon There is unevenness

(8) Average light transmittance at a light wavelength of 400 nm to 500 nm at an optical path length of 15 mm Using the acrylic block copolymer or thermoplastic polymer composition obtained in the following examples or comparative examples, T-die extrusion A 3 mm thick sheet-like molded product molded at a cylinder temperature and a die temperature of 220 ° C. by a molding machine is laminated until it reaches 15 mm, and a spectrophotometer (manufactured by Hitachi High-Technologies Corporation) is used as a D65 light source, 2 ° viewing angle, temperature 25 The light transmittance was measured at ° C.

  In the synthesis examples shown below, the compound was dried and purified by a conventional method and degassed with nitrogen. The compound was transferred and supplied in a nitrogen atmosphere.

[Reference Example 1] [Organic Aluminum Compound: Preparation of Isobutylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum]
After drying with sodium, 25 ml of dry toluene obtained by distillation under an argon atmosphere and 11 g of 2,6-di-t-butyl-4-methylphenol were placed in a 200 ml flask whose internal atmosphere was replaced with argon. Added and dissolved with stirring at room temperature. To the obtained solution, 6.8 ml of triisobutylaluminum was added and stirred at 80 ° C. for about 18 hours, whereby the corresponding organoaluminum compound [isobutylbis (2,6-di-t-butyl-4-methylphenoxy)] was obtained. A toluene solution containing [aluminum] at a concentration of 0.6 mol / l was prepared.

[Reference Example 2] [Synthesis of acrylic block copolymer (A1)]
A two-liter three-necked flask was fitted with a three-way cock, and the inside was deaerated and replaced with nitrogen. Then, at room temperature, 1040 g of dry toluene, 100 g of 1,2-dimethoxyethane, and isobutylbis (2,6-di-) of Reference Example 1 were used. 45 g of a toluene solution containing 30 mmol of (t-butyl-4-methylphenoxy) aluminum was added, and 7.3 mmol of sec-butyllithium was further added. To this, 64 g of methyl methacrylate was added and reacted at room temperature for 1 hour, and then 0.1 g of the reaction solution was collected. This is designated as sampling sample 1. Subsequently, the internal temperature of the polymerization solution was cooled to −25 ° C., and 184 g of n-butyl acrylate was added dropwise over 2 hours. After completion of dropping, 0.1 g of the reaction solution was collected. This is designated as sampling sample 2. Subsequently, 161 g of methyl methacrylate was added, and the reaction solution was returned to room temperature and stirred for 8 hours. The polymerization was stopped by adding 4 g of methanol to the reaction solution. The reaction solution after termination of the polymerization was poured into a large amount of methanol to obtain a deposited precipitate. This is designated as sampling sample 3. ¹ H-NMR measurement and GPC measurement were performed using sampling samples 1 to 3, and based on the results, Mw (weight average molecular weight), Mw / Mn (molecular weight distribution), methyl methacrylate polymer (PMMA) block and When the mass ratio of the n-butyl acrylate polymer (PnBA) block and the like were determined, the finally obtained precipitate was a PMMA block-PnBA block-PMMA block triblock copolymer (PMMA-b- PwBA-b-PMMA), the Mw of the 1st-PMMA block part obtained by the polymerization of the first supplied monomer (MMA) is 9,700, and Mw / Mn is 1.08. Moreover, Mw of the whole triblock copolymer is 62,000, Mw / Mn is 1.11. The ratio of each polymer block is PMMA (14% by mass). ) -PnBA (50 mass%)-PMMA (36 mass%).

[Reference Example 3] [Synthesis of acrylic block copolymer (A2)]
A two-liter three-necked flask was fitted with a three-way cock, and the inside was deaerated and replaced with nitrogen. Then, at room temperature, 1040 g of dry toluene, 100 g of 1,2-dimethoxyethane, and isobutylbis (2,6-di-) of Reference Example 1 were used. 48 g of a toluene solution containing 32 mmol of (t-butyl-4-methylphenoxy) aluminum was added, and 8.1 mmol of sec-butyllithium was further added. To this, 72 g of methyl methacrylate was added and reacted at room temperature for 1 hour, and then 0.1 g of the reaction solution was collected. This is designated as sampling sample 4. Subsequently, the internal temperature of the polymerization solution was cooled to −25 ° C., and 307 g of n-butyl acrylate was added dropwise over 2 hours. After completion of dropping, 0.1 g of the reaction solution was collected. This is designated as sampling sample 5. Subsequently, 72 g of methyl methacrylate was added, and the reaction solution was returned to room temperature and stirred for 8 hours. The polymerization was stopped by adding 4 g of methanol to the reaction solution. The reaction solution after termination of the polymerization was poured into a large amount of methanol to obtain a deposited precipitate. This is designated as sampling sample 6. ¹ H-NMR measurement and GPC measurement were performed using sampling samples 4 to 6, and based on the results, Mw (weight average molecular weight), Mw / Mn (molecular weight distribution), methyl methacrylate polymer (PMMA) block and When the mass ratio of the n-butyl acrylate polymer (PnBA) block and the like were determined, the finally obtained precipitate was a PMMA block-PnBA block-PMMA block triblock copolymer (PMMA-b- PnBA-b-PMMA), and the Mw of the 1st-PMMA block part obtained by polymerization of the first supplied monomer (MMA) is 9,900, and Mw / Mn is 1.08. In addition, Mw of the entire triblock copolymer is 62,000, Mw / Mn is 1.19, and the ratio of each polymer block is PMMA (16% by mass). ) -PnBA (68% by mass) -PMMA (16% by mass).

[Examples 1 to 11 and Comparative Examples 1 to 4]
Acrylic block copolymers (A1) and (A2) obtained in the above reference example, and acrylic resin (B) -1 (“Parapet H1000B” manufactured by Kuraray Co., Ltd., MFR: 22 g / 10 min (230 ° C., 37 .3N)), (B) -2 ("Parapet GF" manufactured by Kuraray Co., Ltd., MFR: 15 g / 10 min (230 ° C, 37.3N)), (B) -3 ("Parapet EH" manufactured by Kuraray Co., Ltd.) , MFR: 1.3 g / 10 min (230 ° C., 37.3 N)), (B) -4 (“Parapet HRL” manufactured by Kuraray Co., Ltd.), MFR: 2.0 g / 10 min (230 ° C., 37.3 N) ) And (B) -5 (“Parapet G” manufactured by Kuraray Co., Ltd., MFR: 8.0 g / 10 min (230 ° C., 37.3 N)) at a blending ratio shown in Table 1 below, twin screw extruder After kneading at 230 ° C by And, by cutting, to prepare pellets of the thermoplastic polymer composition. Using this pellet, T-die extrusion molding was carried out at 190 ° C. to 210 ° C. to produce sheet-like molded bodies having a thickness of 0.1 mm and 3 mm. A test piece was collected from the sheet-like molded article, and the average light transmittance at a light wavelength of 400 nm to 500 nm at an optical path length of 15 mm was measured or evaluated. The obtained results are shown in Tables 1 and 2.

  From the results of Table 1 and Table 2, when using the thermoplastic polymer compositions obtained in Examples 1 to 3 of the present invention, the transparency and surface smoothness are excellent without impairing flexibility, Furthermore, it turns out that the sheet-like molded object excellent in the balance with the light transmittance of short wavelength light is obtained. On the other hand, Comparative Example 1 is composed only of the acrylic block copolymer (A1) and does not contain the acrylic resin (B). Therefore, when extrusion molding is performed, fine streak-like irregularities are formed on the surface of the sheet-like molded body. It can be seen that a good molded product cannot be obtained and the average light transmittance at a light wavelength of 400 nm to 500 nm at an optical path length of 15 mm is low. Moreover, since Comparative Example 2 consists only of the acrylic block copolymer (A1) and the acrylic block copolymer (A2), when extrusion molding is performed, a fine streak-like surface is formed on the surface of the sheet or film-shaped molded body. It can be seen that unevenness is generated and a good molded product cannot be obtained, and the average light transmittance at a light wavelength of 400 nm to 500 nm at an optical path length of 15 mm is low. Furthermore, since Comparative Example 3 consists only of an acrylic block copolymer (A1) and an acrylic resin (B) having an MFR of 15 g / 10 min or more, it is poor in flexibility and transparency, and when extruded. It can be seen that fine streak-like irregularities are generated on the surface of the sheet-like molded body, and a good molded body cannot be obtained, and the average light transmittance at an optical wavelength of 400 nm to 500 nm at an optical path length of 15 mm is low. Since Comparative Example 4 consists only of the acrylic block copolymer (A1) and the acrylic resin (B) having an MFR of less than 15 g / 10 min, it is poor in flexibility, and also has surface smoothness and molding processability. It turns out that it is inferior compared with 1-11. On the other hand, Examples 4-11 are acrylic resin (B) -3, acrylic resin (B) -4, and acrylic resin (B) whose melt flow rate in 230 degreeC and 37.3N is respectively less than 15 g / 10min. Since it contains -5, the surface smoothness of the surface of the sheet-like molded article is good as in Examples 1 to 3 when extrusion molding is performed. Moreover, it exists in the tendency for the average light transmittance in light wavelength 400nm -500nm to be high compared with the sheet-like molded object obtained in Comparative Examples 1-4. In Examples 4 to 11, the compatibility of the acrylic block copolymer (A) with the acrylic resin (B) -3, the acrylic resin (B) -4, and the acrylic resin (B) -5 included in each of them is Compared with Examples 1 to 3 using an acrylic resin having a melt flow rate of 15 g / 10 min or more, the light wavelength tends to be large, especially in the long optical path, since the light loss tends to be large in the long optical path. There exists a tendency for the average light transmittance in 400 nm-500 nm to be low.

  The thermoplastic polymer composition of the present invention is suitable as a molding material because it has excellent surface smoothness and molding processability, is excellent in flexibility, and has a high light transmittance for short-wavelength light. Moreover, since the sheet-like molded object which consists of a thermoplastic polymer composition of this invention is excellent in a softness | flexibility and the light transmittance of short wavelength light is high, it can be used suitably for various uses.

Claims (6)

A thermoplastic polymer composition comprising an acrylic block copolymer (A) and an acrylic resin (B);
The acrylic block copolymer (A) has a molecular structure in which a polymer block (a2) mainly composed of methacrylate units is bonded to both ends of the polymer block (a1) mainly composed of acrylate units. An acrylic block copolymer having at least one thereof, having a weight average molecular weight of 10,000 to 100,000;
Content of acrylic block copolymer (A1) and polymer block (a2) in which acrylic block copolymer (A) has a content of polymer block (a2) of 50 % by mass or more and 65 % by mass or less Including an acrylic block copolymer (A2) having a content of 15 % by mass or more and less than 40% by mass;
The acrylic resin (B) is mainly composed of methacrylate units;
A thermoplastic polymer composition having a mass ratio [(A) / (B)] of the acrylic block copolymer (A) and the acrylic resin (B) of 97/3 to 10/90.   2. The thermoplastic polymer composition according to claim 1, wherein the acrylic resin (B) has a melt flow rate at 230 ° C. and 37.3 N of 15 g / 10 min or more.   2. The thermoplastic polymer composition according to claim 1, wherein the acrylic resin (B) has a melt flow rate at 230 ° C. and 37.3 N of less than 15 g / 10 minutes.   The thermoplastic polymer composition according to any one of claims 1 to 3, wherein the content of the acrylic block copolymer (A1) is 5% by mass or more based on the total amount of the acrylic block copolymer (A). .   The sheet-like molded object which consists of a thermoplastic polymer composition in any one of Claims 1-4.   A D65 light source obtained by a spectral light transmittance measurement method, characterized by having an average light transmittance of 40% or more at a light wavelength of 400 nm to 500 nm at a 2 ° viewing angle, a measurement temperature of 25 ° C., and an optical path length of 15 mm, The sheet-like molded object according to claim 5.